Internet connectivity has transformed life everywhere as more people connect to the Internet to chat with friends and family, watch videos, listen to streamed music, or conduct online banking and e-commerce. The two primary means for access to the Internet are wired broadband and wireless. Current wired broadband Internet access is based on three different standards: Digital Subscriber Line (DSL); Data Over Cable Service Interface Specification (DOCSIS); and Fiber-to-Home (FTTH). The wireless access is based on two standards: Wide Area Network (WAN), also referred to as the Fourth Generation Long. Term Evolution (4G LTE); and Local Area Network (LAN), also referred to as Wi-Fi. Wi-Fi is generally used indoors as short-range wireless extension of wired broadband systems. The 4G LTE on the other hand provides wide area long-range connectivity using dedicated infrastructure such as cell towers and backhaul to connect to the Internet.
In order to address the rapid growth in data traffic, next generation WLAN and cellular systems are expected to operate at higher frequencies where abundant spectrum is available. For example, at millimeter wave frequencies (28 GHz and above), radio spectrum use is lighter. A large number of small antennas operating at millimeter wave frequencies may be used to provide the increased capacity in the future. The small size antennas are enabled by carrier waves that are millimeters long compared to centimeter long waves at currently used lower frequencies.
In order to provide Gb/s data rates to users in an urban and sub-urban setting, a highly dense deployment of base stations (BS) or access points (APs) is envisaged. It is fairly common in cellular systems for each BS to have 3 or more sectors. Even with the LTE-advanced deployments, wherein a 3-sector BS serves many tens of users, it is challenging to obtain 10 Gb/s per BS site. With fifth generation (5G) network's goal of providing Gb/s data rates to end users, the number of sectors per BS/AP is expected to increase multi-fold and the inter site distances (ISDs) are set to reduce. However, a multi-fold increase in the number of sectors per BS/AP along with a reduction in the ISDs will increase interferences in wireless signals. Accordingly, in a densely deployed wireless network, improved interference management in necessary.